IAEA-RGK-1
, Potassium Sulfate

The IAEA-RGK-1 material is produced from high purity (99.8%) potassium sulphate supplied by the Merck Company. The potassium property value and its uncertainty were obtained from repeated measurements performed at the IAEA Laboratories Seibersdorf and the results confirmed the value certified by Merck. The upper limits for the uranium and thorium property values were estimated by the IAEA Laboratories Seibersdorf using fluorimetry and activation analysis, respectively.

Analyte

Value

Unit

95% C.I.

N

R/I/C

40K

14000?

Bq/kg

13600 - 14400

20

R

K

448000

mg/kg

445000 - 451000

20

R

Th

< 0.01

mg/kg

-

20

I

U

< 0.001

mg/kg

-

20

I

(Value) Concentration calculated as a mean of the accepted laboratory means
(N) Number of accepted laboratory means which are used to calculate the recommended or
information values and their respective confidence intervals
(R/I/C) Classification assigned to the property value for analyte (Recommended/Information/Certified)
(?) Natural radionuclide activity concentrations derived from the elemental concentrations on basis of isotopic abundance and half-life data

The values listed above were established on the basis of a gravimetric dilution of materials with known uranium, thorium and potassium composition. The details concerning the criteria for qualification as a recommended or information value can be found in the respective report (attached).